Northern Saw-whet Owl Recaps
Categories: Research
Written by Olivia Maillet
Since 2001, PEPtBO has been monitoring Northern Saw-whet Owl migration each fall through a targeted research study. Northern Saw-whet Owls are very tiny - they are approximately the size of an American Robin, and they can weigh as little as a chicken egg (~75 g) and as much as deck of cards (~110 g). Once captured in our nets, each owl receives a metal band with a unique 9-digit code on its leg, perfectly sized and shaped for their short legs. This unique code is forever connected to the data we collected when we originally banded the owl.
These owls are often recaptured, meaning a banded bird is captured in a net again. Recaptures can be organized in a few ways: within a night (maybe an hour later), within a season (maybe the next night!), between years, within a station, or even between stations! The most interesting recaptures often happen between stations. These are referred to as “foreign recaptures” and “foreign recoveries”, where owls banded at PEPtBO are later recaptured at another banding station using the same methods, or owls banded at another banding station are recaptured at PEPtBO.
Between 2019-2024, there were 146 recaptures and recoveries. In 2024 alone, PEPtBO recaptured 10 owls banded at other stations, with original banding locations up to 717 km away! Recaptures at PEPtBO occurred as far north as Hilliardton, ON, and Tadoussac, QC, and as far south as Assateague Island, MD, and Bergton, VI. Even stations as far west as Minnesota and as far east as Nova Scotia have recaptured owls banded at PEPtBO!
Why are recaptures important?
Some of the most valuable data comes from recaptures. Here are just a few of the questions that can be answered using Northern Saw-whet Owl recapture data:
How long do Northern Saw-whet Owls stop over?
Tracking data show that Northern Saw-whet Owl stopovers last 2-13 days.
How long do Northern Saw-whet Owls live?
The oldest known Northern Saw-whet Owl was 9 years 5 months old, originally banded in Ontario in 1999 and recaptured in Minnesota in 2007.
Based on their migration pathways and strategies, what hazards could they encounter along the way? Think windows, wind turbines, anthropogenic noise and light
Researchers demonstrated through experiments that anthropogenic noise impairs the Northern Saw-whet Owls ability to hunt
You can support our Northern Saw-whet Owl program through donations and ticket sales to our owl events where you may have a chance to see them up close. Tickets go on sale in September of each year and are offered to members first.